To produce fibre composite components, moulds are often used into which fibre material which is to be infiltrated with resin is introduced. The fibre material is then covered, for example with a gas-tight sheath which can be sealed off from the mould, and resin is infiltrated in at least one place of the “infusion structure” thus formed, in that a vacuum is produced in the gas-tight sealed interior of the structure in at least one other place of the structure. This method known as the vacuum infusion technique is used, for example in the “Seaman composites resin infusion moulding” (SCRIMP) process, in the “vacuum assisted resin transfer moulding” (VARTM) process, in the “vacuum assisted resin injection” (VARI) process or in the “vacuum assisted process” (VAP). A VAP process should be understood as a variant of a low-pressure infiltration technique for example.
To achieve a high-quality finished fibre composite component, it is important that during the resin infiltration procedure, the resin saturates the fibre material as uniformly as possible, i.e. for example an excessive flow resistance does not develop anywhere in the interior of the infusion structure. To introduce the resin as uniformly as possible into all of the fibre material, it is possible to interpose between the sheath and the fibre material pressure-resistant structures having flow channels, for example in the form of wide-mesh textile fabrics (for example woven fabrics, knitted fabrics, interlaced fabrics) or latticed mats. Structures of this type, which are introduced into the infusion structure together with the fibre material to be infiltrated, for conveying a fast and/or particularly uniform resin distribution in the fibre material are usually known as “flow aids”. In other cases, flow channels which are open towards the fibre material, i.e. furrow-like grooves, are provided directly in the mould.
U.S. Pat. No. 6,656,411 B1 discloses a mould for producing fibre composite components which has a support surface for holding a first layer of fibre material, a pressure-tight intermediate piece having furrow-like channels on an upper surface and on a lower surface being arranged on the first layer of fibre material. A second layer of fibre material is arranged on the intermediate piece. A gas-tight sheath is provided on the second layer of fibre material. Resin can be conducted through the channels to the two layers on the surfaces on either side of the intermediate piece. The flow of resin is produced by a pressure difference generated by a vacuum pump.
A disadvantage of this prior art is that an excess of resin is generally unavoidable. A large amount of residual, unused resin material usually remains in the distributor media and/or on the fibre composite component to be produced.
U.S. Pat. No. 6,406,659 B1 discloses a mould for producing fibre composite components which has a support surface for holding fibre material which is to be infiltrated with resin, a first gas-tight film being arranged over the fibre material, and a pressure-tight intermediate piece having furrow-like channels being provided between said first film and a second gas-tight film. By applying a pressure difference, the first film can detach itself from the fibre material and instead can be placed in the channels of the intermediate piece. In this manner, distributor channels can be provided directly on the surface of the fibre material. The second film can facilitate the generation of the pressure difference.
A disadvantage of this prior art is that a large number of components is required and that adjusting the pressure difference requires a relatively large outlay in terms of apparatus and a relatively great control effort in terms of the process.